This invention relates to comminutor devices having significant solid material content carried by a flowing liquid, such as sewage for example, in an in-line pipe system. The present invention is concerned primarily with an improved stationary cage structure and an improved rotatable cutting and shredding member. In the prior art comminutors may have had fixed cages generally formed of a plurality of individual axially spaced-apart sections forming slots for the passage of the comminuted sewage, such devices may also have associated separte stationary cutting and shredding bars, commonly referred to as cutter bars connected to such cages, in proximity to the bars having teeth formed thereon which may be in axial alignment with corresponding sections of the slots formed in the fixed cage. The comminutor may have further means mounted in close spaced relationship with the fixed cage and separate cutter bars for interengaging comminuting action.
Comminutors of the foregoing types are well known and described in the prior art, for example such as in U.S. Pat. No. 2,305,935, to George L. Thon, issued Dec. 22, 1942. In this device the comminution of material contained in the sewage is accomplished by a slotted straining member, either stationary or rotary, which intercepts pieces of material which are too large to pass through the strainer slots and having cutting teeth which cooperate with one or more associated notched cutting bars to cut, shrear or tear intercepted solids into pieces small enough to pass through the slots. In operation, comminution of the solid materials occurs on the concave side of the strainer where a plurality of cutting teeth are disposed in the path of travel of the notches in the cutting bar, either one or more spaced about the axis of rotation of such bar or bars, whereby pieces are cut, shreared or torn from the solids that are caught between the cutting bar or bars and the cutting teeth.
U.S. Pat. No. 2,389,309, to Walter H. Green, issued Nov. 20, 1945, discloses in its preferred embodiment, a fixed semi-cylindrical grid forming a plurality of horizontal slots extending circumferentially to the grid having a plurality of rotatable circular discs having cutting teeth on the peripheries of the discs by extending through the slots of the grid and a vertical cutter bar set into the wall of the conduit extending vertically along the periphery of the rotatable discs. In operation, larger solids in the sewage are first caught or held by the upstream segments of the rotating plate which extend outwardly beyond the bars of the fixed grid, and will be nibbled away by the rotating or washed or carried over to the cutter bar. Thus, such solids are caught between the cutting bar and into the down stream flow of sewage.
U.S. Pat. No. 2,594,785, to Herbert J. Meeker, issued Apr. 29, 1952, discloses a comminutor having a vertical stationary semi-cylindrical bar cage having a plurality of screening openings therein, further having one or more internal oscillating cutter arms together with means for oscillating the cutter arms backwards and forwards over the concave surface of the cage. Each cutter arm carries shredding teeth which cooperate with shredding teeth removably carried by the bar cage to cut and shred collected screening openings in the semi-cylindrical cage. The cutter bar attached to the oscillating cutter arm or arms extends vertically across the inner concave surface of the semi-cylindrical cage at an acute angle such that the desired shrearing action occurs advantageously.
U.S. Pat. No. 4,186,888, to William B. Galanty, the present inventor, issued Feb. 5, 1980, discloses a comminutor primarily for channels that carry the flow of liquid sewage which includes a stationary semi-cylindrical concave cage formed of a plurality of axially spaced-apart individual sections of arcuate rings or bars connected together arcuately and axially. A plurality of separate comb-like members are mounted vertically at predetermined spaced intervals along the inner surface contour of the semi-cylindrical concave cage member with the teeth of its comb-like members in axial alignment with corresponding sections of the rings or bars which form the cage member. A plurality of rotatable cutting and shredding arms are mounted axially along a helical spiral-like path extending radially from an axially disposed shaft, in spaced relationship with the cage member and the plurality of comb-like members for interengaging comminuting action with radially extending portions of their respective teeth. The teeth of the cutting and shredding arms may be in engagement with each tooth of the comb-like members and each of the slotted openings of the cage member at least once during each revolution of the cutting and shredding arms.